Wireless electric power transmission is replacing the conventional wired electric power transmission. Electronic devices can be charged without charging lines. For example, a mobile phone can be charged directly by using a wireless charging device without a charging line.
An additional wireless charging device needs to be provided for a conventional electronic device to wireless charging the conventional electronic device. For example, a dedicated shell corresponding to a wireless charger is additionally provided outside the mobile phone for performing wireless charging.
However, the additional wireless charging device increases the thickness of electronic devices and affects the appearance of the electronic device.